Methodology for Selection of Rapid Tooling Process for Manufacturing Applications

Abstract

Digital representation of geometry is transforming the methods for the manufacturing of products. Such transformations include a significant reduction in cost and leadtime to produce products and to increase the variety of products. The ability to produce tooling from material removal and additive processes has led to new methods to produce tooling from digital geometry representations. These include processes that are grouped together as fast-free-form-fabrication (FFFF) methods. In addition, other possibilities exist in modular tooling for generating variety and new processes/methods for producing such geometries. Also, conventional machining processes have improved significantly. As a result of these transformations, a tooling designer faces many choices of methods, materials, and lead-times to produce tooling. These decisions involve geometric reasoning coupled with other requirements based on production needs, cost constraints, and individual casting shop capabilities. This paper discusses a methodology for selection of rapid tooling (RT) processes based on a number of user-specified attributes and relative cost and lead-time comparisons across a wide spectrum of available RT processes. The method is based on a combination of weighted functionals and on the approximate mathematical models of metalcasting process costs and their lead-time. The method has been put on the Internet for easy access. It is currently limited to only several of the most common RT processes and materials. However, the database will be expanded in the future to include a majority if not all of the metalcasting processes.